Solid-state imaging device and electronic apparatus

ABSTRACT

The present technology relates to a solid-state imaging device and an electronic apparatus capable of improving sensitivity while suppressing deterioration of color mixing. The solid-state imaging device includes: a substrate; a first photoelectric conversion region that is provided in the substrate; a second photoelectric conversion region that is provided in the substrate; a trench that is provided between the first photoelectric conversion region and the second photoelectric conversion region and penetrates through the substrate; a first concave portion region that has a plurality of concave portions provided on a light receiving surface side of the substrate, above the first photoelectric conversion region; and a second concave portion region that has a plurality of concave portions provided on the light receiving surface side of the substrate, above the second photoelectric conversion region. The technology of the present disclosure can be applied to, for example, a backside illumination solid-state imaging device and the like.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of U.S. patentapplication Ser. No. 16/959,709, filed on Jul. 2, 2020, which is a U.S.National Phase of International Patent Application No. PCT/JP2018/048418filed on Dec. 28, 2018, which claims priority benefit of Japanese PatentApplication No. JP 2018-002367 filed in the Japan Patent Office on Jan.11, 2018. Each of the above-referenced applications is herebyincorporated herein by reference in its entirety.

TECHNICAL FIELD

The present technology relates to a solid-state imaging device and anelectronic apparatus, and, for example, to a solid-state imaging deviceand an electronic apparatus capable of improving sensitivity whilesuppressing deterioration of color mixing.

BACKGROUND ART

In a solid-state imaging device, as a structure for preventingreflection of incident light, it has been proposed to provide a fineconcave-convex structure at an interface on a light receiving surfaceside of a silicon layer on which a photodiode is formed (for example,Patent Documents 1 and 2).

CITATION LIST Patent Document

Patent Document 1: Japanese Patent Application Laid-Open No. 2010-272612

Patent Document 2: Japanese Patent Application Laid-Open No. 2013-33864

SUMMARY OF THE INVENTION Problems to be Solved by the Invention

However, the fine concave-convex structure can improve sensitivity bypreventing the reflection of incident light, but scattering becomes alsolarge and an amount of light leaking into adjacent pixels is increased,and thus, there has been a possibility that color mixing would bedeteriorated.

The present disclosure has been made in view of such a situation, and anobject of the present disclosure is to improve sensitivity whilesuppressing deterioration of color mixing.

Solutions to Problems

A solid-state imaging device according to an aspect o the presenttechnology includes: a substrate; a first photoelectric conversionregion that is provided in the substrate; a second photoelectricconversion region that is provided in the substrate; a trench that isprovided between the first photoelectric conversion region and thesecond photoelectric conversion region and penetrates through thesubstrate; a first concave portion region that has a plurality ofconcave portions provided on a light receiving surface side of thesubstrate, above the first photoelectric conversion region; and a secondconcave portion region that has a plurality of concave portions providedon the light receiving surface side of the substrate, above the secondphotoelectric conversion region.

An electronic apparatus according to an aspect of the present technologyincludes the solid-state imaging device described above.

The solid-state imaging device according to an aspect of the presenttechnology includes the first photoelectric conversion region and thesecond photoelectric conversion region provided in the substrate, thetrench provided between the first photoelectric conversion region andthe second photoelectric conversion region and penetrating through thesubstrate, the first concave portion region having the plurality ofconcave portions provided on the light receiving surface side of thesubstrate, above the first photoelectric conversion region, and thesecond concave portion region having the plurality of concave portionsprovided on the light receiving surface side of the substrate, above thesecond photoelectric conversion region.

The electronic apparatus according to an aspect of the presenttechnology includes the solid-state imaging device described above.

Note that the solid-state imaging device and the electronic apparatusmay be independent devices or may be internal blocks configuring onedevice.

Effects of the Invention

According to the embodiments of the present technology, it is possibleto improve sensitivity while suppressing deterioration of color mixing.

Note that an effect described here is not necessarily limited, and maybe any effect described in the present disclosure.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a diagram illustrating a schematic configuration of asolid-state imaging device according to the present disclosure.

FIG. 2 is a diagram illustrating a cross-sectional configuration exampleof a pixel according to a first embodiment.

FIG. 3 is a diagram for describing a concave portion region.

FIG. 4 is a diagram for describing a concave portion region.

FIG. 5 is a diagram illustrating a cross-sectional configuration exampleof a pixel according to a second embodiment.

FIGS. 6A and 6B are diagrams for describing an effect of a pixelstructure of the present disclosure.

FIG. 7 is a diagram for describing optimal conditions at various placesof a pixel.

FIG. 8 is a diagram illustrating a cross-sectional configuration exampleof a pixel according to a third embodiment.

FIG. 9 is a diagram illustrating a cross-sectional configuration exampleof a pixel according to a fourth embodiment.

FIG. 10 is a diagram illustrating another cross-sectional configurationexample of a pixel according to the fourth embodiment.

FIG. 11 is a diagram illustrating a cross-sectional configurationexample of a pixel according to a fifth embodiment.

FIG. 12 is a diagram illustrating a cross-sectional configurationexample of a pixel according to a sixth embodiment.

FIG. 13 is a diagram illustrating a cross-sectional configurationexample of a pixel according to a seventh embodiment.

FIG. 14 is a diagram illustrating a cross-sectional configurationexample of a pixel according to an eighth embodiment.

FIG. 15 is a diagram illustrating a cross-sectional configurationexample of a pixel according to a ninth embodiment.

FIG. 16 is a diagram illustrating a cross-sectional configurationexample of a pixel according to a tenth embodiment.

FIG. 17 is a diagram illustrating a cross-sectional configurationexample of a pixel according to an eleventh embodiment.

FIG. 18 is a diagram illustrating a cross-sectional configurationexample of a pixel according to a twelfth embodiment.

FIG. 19 is a diagram illustrating a cross-sectional configurationexample of a pixel according to a thirteenth embodiment.

FIG. 20 is a block diagram illustrating a configuration example of animaging device as an electronic apparatus according to the presentdisclosure.

FIG. 21 is a diagram illustrating an example of a schematicconfiguration of an endoscopic surgery system.

FIG. 22 is a block diagram illustrating an example of functionalconfigurations of a camera head and a camera control unit (CCU).

FIG. 23 is a block diagram illustrating an example of a schematicconfiguration of a vehicle control system.

FIG. 24 is an explanatory diagram illustrating an example ofinstallation positions of an outside-vehicle information detection unitand an imaging unit.

MODE FOR CARRYING OUT THE INVENTION

Hereinafter, modes (hereinafter, referred to as embodiments) forcarrying out the present technology will be described.

<Schematic Configuration Example of Solid-State Imaging Device>

FIG. 1 illustrates a schematic configuration of a solid-state imagingdevice according to the present disclosure.

The solid-state imaging device 1 of FIG. 1 includes a pixel array unit 3in which pixels 2 are arranged in a two-dimensional array shape and aperipheral circuit unit arranged around the pixel array unit 3, on asemiconductor substrate 12 using, for example, silicon (Si) as asemiconductor. The peripheral circuit unit includes a vertical drivecircuit 4, column signal processing circuits 5, a horizontal drivecircuit 6, an output circuit 7, a control circuit 8, and the like.

The pixel 2 includes a photodiode as a photoelectric conversion elementand a plurality of pixel transistors. The plurality of pixel transistorsincludes, for example, four metal oxide semiconductor (MOS) transistors,that is, a transfer transistor, a selection transistor, a resettransistor, and an amplification transistor.

Furthermore, the pixel 2 can also have a shared pixel structure. Thisshared pixel structure includes a plurality of photodiodes, a pluralityof transfer transistors, one shared floating diffusion region, and oneother pixel transistor that is shared. That is, in a shared pixel,photodiodes and transfer transistors that configure a plurality of unitpixels are configured to share one other pixel transistor with eachother.

The control circuit 8 receives an input clock and data instructing anoperation mode and the like, and outputs data such as internalinformation of the solid-state imaging device 1. That is, the controlcircuit 8 generates a clock signal or a control signal which is areference for operations of the vertical drive circuit 4, the columnsignal processing circuits 5, the horizontal drive circuit 6, and thelike, on the basis of a vertical synchronization signal, a horizontalsynchronization signal, and a master clock. Then, the control circuit 8outputs the generated clock signal or control signal to the verticaldrive circuit 4, the column signal processing circuits 5, the horizontaldrive circuit 6, and the like.

The vertical drive circuit 4 is configured by, for example, a shiftregister, selects pixel drive wirings 10, supplies pulses for drivingthe pixels 2 to the selected pixel drive wirings 10, and drives thepixels 2 in row units. That is, the vertical drive circuit 4 selectivelyscans each pixel 2 of the pixel array unit 3 sequentially in thevertical direction in row units, and supplies pixel signals based onsignal charges generated according to amounts of received light in aphotoelectric conversion unit of each pixel 2 to the column signalprocessing circuits 5 through vertical signal lines 9.

The column signal processing circuit 5 is arranged for every column ofthe pixels 2, and performs signal processing such as noise removal onsignals output from the pixels 2 of one row for every pixel column. Forexample, the column signal processing circuit 5 performs signalprocessing such as correlated double sampling (CDS) processing, andanalog-to-digital (AD) conversion processing, for removing fixed patternnoise unique to the pixels.

The horizontal drive circuit 6 is configured by, for example, a shiftregister, sequentially selects each of the column signal processingcircuits 5 by sequentially outputting horizontal scanning pulses, andoutputs pixel signals from each of the column signal processing circuits5 to a horizontal signal line 11.

The output circuit 7 performs signal processing on the signalssequentially supplied from each of the column signal processing circuits5 through the horizontal signal line 11, and outputs the processedsignals. For example, the output circuit 7 may perform only buffering ormay perform black level adjustment, column variation correction, variousdigital signal processing, and the like. An input/output terminal 13exchanges signals with the outside.

The solid-state imaging device 1 configured as described above is a CMOSimage sensor called a column AD manner in which the column signalprocessing circuit 5 performing the CDS processing and the AD conversionprocessing is arranged for every pixel column.

Furthermore, the solid-state imaging device 1 is a backside illuminationMOS solid-state imaging device in which light is incident from a backsurface side opposite to a front surface side of the semiconductorsubstrate 12 on which the pixel transistors are formed.

Pixel Structure According to First Embodiment

FIG. 2 is a diagram illustrating a cross-sectional configuration exampleof a pixel 2 a according to a first embodiment.

The solid-state imaging device 1 includes the semiconductor substrate 12and a multilayer wiring layer 21 and a support substrate 22 formed on afront surface side (a lower side in the drawing) of the semiconductorsubstrate 12.

The semiconductor substrate 12 includes, for example, silicon (Si) andis formed to have a thickness of, for example, 1 to 6 μm. In thesemiconductor substrate 12, for example, an N-type (secondconductivity-type) semiconductor region 42 is formed for every pixel 2 ain a P-type (first conductivity-type) semiconductor region 41, such thata photodiode PD is formed in pixel units. The P-type semiconductorregions 41 provided on front and back surfaces of the semiconductorsubstrate 12 also serve as hole charge accumulation regions forsuppressing a dark current.

Note that at a pixel boundary of each pixel 2 a between the N-typesemiconductor regions 42, the P-type semiconductor region 41 is dug in astate where it penetrates through the semiconductor substrate 12, asillustrated in FIG. 2 , in order to form an inter-pixel light shieldingportion 47 as described later.

An interface (interface on a light receiving surface side) of the P-typesemiconductor region 41 above the N-type semiconductor region 42 whichis a charge accumulation region is configured to prevent reflection ofincident light by a concave portion region 48 forming a fineconcave-convex structure. The concave portion region 48 will be furtherdescribed with reference to FIGS. 3 and 4 .

The multilayer wiring layer 21 includes a plurality of wiring layers 43and an interlayer insulating film 44. Furthermore, in the multilayerwiring layer 21, a plurality of pixel transistors Tr for performingreadout and the like of charges accumulated in the photodiodes PD arealso formed.

On a back surface side of the semiconductor substrate 12, a pinninglayer 45 is formed so as to cover an upper surface of the P-typesemiconductor region 41. The pinning layer 45 is formed using a highdielectric having a negative fixed charge so that a positive charge(hole) accumulation region is formed at an interface portion with thesemiconductor substrate 12 to suppress generation of a dark current. Byforming the pinning layer 45 so as to have the negative fixed charge, anelectric field is applied to an interface with the semiconductorsubstrate 12 by the negative fixed charge, and the positive chargeaccumulation region is thus formed.

As the pinning layer 45, a Si cover film (SCF) can be used. Furthermore,the pinning layer 45 is formed using, for example, hafnium oxide (HfO₂).Furthermore, the pinning layer 45 may be formed using zirconium dioxide(ZrO₂), tantalum oxide (Ta₂O₅), or the like.

A transparent insulating film 46 is embedded in a penetration portion ofthe P-type semiconductor region 41, and is formed on the entire backsurface side above the pinning layer 45 of the semiconductor substrate12. The penetration portion of the P-type semiconductor region 41 inwhich the transparent insulating film 46 is embedded configures aninter-pixel light shielding portion 47 preventing leakage of incidentlight from adjacent pixels 2 a.

The transparent insulating film 46 includes a material that transmitslight, has an insulating property, and has a refractive index n1 smallerthan a refractive index n2 of the semiconductor regions 41 and 42(n1<n2). As the material of the transparent insulating film 46, siliconoxide (SiO₂), silicon nitride (SiN), silicon oxynitride (SiON), hafniumoxide (HfO₂), aluminum oxide (Al₂O₃), zirconium oxide (ZrO₂), tantalumoxide (Ta₂O₅), titanium oxide (TiO₂), lanthanum oxide (La₂O₃),praseodymium oxide (Pr₂O₃), cerium oxide (CeO₂), neodymium oxide(Nd₂O₃), promethium oxide (Pm₂O₃), samarium oxide (Sm₂O₃), europiumoxide (Eu₂O₃), gadolinium oxide (Gd₂O₃), terbium oxide (Tb₂O₃),dysprosium oxide (Dy₂O₃), holmium oxide (Ho₂O₃), thulium oxide (Tm₂O₃),ytterbium oxide (Yb₂O₃), lutetium oxide (Lu₂O₃), yttrium oxide (Y₂O₃), aresin, or the like, can be used alone or in combination.

Note that an antireflection film may be stacked on the pinning layer 45before forming the transparent insulating film 46. As a material of theantireflection film, silicon nitride (SiN), hafnium oxide (HfO₂),aluminum oxide (Al₂O₃), zirconium oxide (ZrO₂), tantalum oxide (Ta₂Ta₅),titanium oxide (TiO₂), lanthanum oxide (La₂O₃), praseodymium oxide(Pr₂O₃), cerium oxide (CeO₂), neodymium oxide (Nd₂O₃), promethium oxide(Pm₂O₃), samarium oxide (Sm₂O₃), europium oxide (Eu₂O₃), gadoliniumoxide (Gd₂O₃), terbium oxide (Tb₂O₃), dysprosium oxide (Dy₂O₃), holmiumoxide (Ho₂O₃), thulium oxide (Tm₂O₃), ytterbium oxide (Yb₂O₃), lutetiumoxide (Lu₂O₃), yttrium oxide (Y₂O₃), or the like, can be used.

The antireflection film may be formed only on an upper surface of theconcave portion region 48 or may be formed on both of the upper surfaceof the concave portion region 48 and a side surface of the inter-pixellight shielding portion 47, similar to the pinning layer 45.

A light shielding film 49 is formed in a region of the pixel boundary onthe transparent insulating film 46. A material of the light shieldingfilm 49 may be any material that shields light, and for example,tungsten (W), aluminum (Al), copper (Cu), or the like can be used as thematerial of the light shielding film 49.

A flattening film 50 is formed on the entire upper surface of thetransparent insulating film 46 as well as the light shielding film 49.As a material of the flattening film 50, for example, an organicmaterial such as a resin can be used.

On the flattening film 50, a color filter layer 51 of red, green, orblue is formed for every pixel. The color filter layer 51 is formed, forexample, by spin-coating a photosensitive resin containing a coloringmatter such as a pigment or a dye. Each color of red, green, and blue isarranged, for example, in a Bayer array, but may be arranged in anotherarray manner. In the example of FIG. 2 , a color filter layer 51 of blue(B) is formed in a right pixel 2 a, and a color filter layer 51 of green(G) is formed in a left pixel 2 a.

On the color filter layer 51, an on-chip lens 52 is formed for everypixel 2 a. The on-chip lens 52 includes, for example, a resin-basedmaterial such as a styrene resin, an acrylic resin, a styrene-acrylcopolymer resin, or a siloxane resin. The incident light is condensed bythe on-chip lens 52, and the condensed light is efficiently incident onthe photodiode PD via the color filter layer 51.

Each pixel 2 a of the pixel array unit 3 of the solid-state imagingdevice 1 is configured as described above.

Here, the concave portion region 48 will be described with reference toFIG. 3 . The concave portion region 48 is a region in which fineconcave-convex portions are formed, and the concave portion and theconvex portion are different from each other depending on where asurface which is a reference (hereinafter referred to as a referencesurface) is located.

Furthermore, the concave portion region 48 is a region having a fineconcave-convex structure formed at the interface (interface on the lightreceiving surface side) of the P-type semiconductor region 41 above theN-type semiconductor region 42 which is the charge accumulation region.This concave-convex structure is formed on a light receiving surfaceside of the semiconductor region 42, in other words, the semiconductorsubstrate 12. Therefore, a predetermined surface of the semiconductorsubstrate 12 can be used as the reference surface, and here, adescription will be continued by taking a case where a part of thesemiconductor substrate 12 is used as the reference surface as anexample.

FIG. 3 is an enlarged view of the vicinity of the concave portion region48. A surface of the concave portion region 48 which is a boundaryportion between the concave portion region 48 and the pinning layer 45and is close to the transparent insulating film 46 is referred to as anupper surface 48-1. Furthermore, a surface of the concave portion region48 which is a boundary portion between the concave portion region 48 andthe pinning layer 45 and is close to the semiconductor region 42 isreferred to as a lower surface 48-2.

Furthermore, it is assumed that a reference surface A is a surface at aposition where the upper surface 48-1 is formed, and it is assumed thata reference surface C is a surface at a position where the lower surface48-2 is formed. It is assumed that a reference surface B is a surfacethat is at a position between the reference surface A and the referencesurface C, in other words, a surface that is at a position between theupper surface 48-1 and the lower surface 48-2.

In a case where the reference surface A is used as a reference, a shapeof the concave portion region 48 is a shape in which concave portionsare present with respect to the reference surface A. That is, in a casewhere the reference surface A is used as the reference, the lowersurface 48-2 is located at a position depressed downward with respect tothe reference surface A (=the upper surface 48-1), such that the concaveportion region 48 becomes a region in which fine concave portions areformed. Moreover, in other words, when the reference surface A is usedas the reference, the concave portion region 48 can be said to be aregion in which the concave portion is formed between the upper surface48-1 and the upper surface 48-1, such that fine concave portions areformed.

In a case where the reference surface C is used as a reference, a shapeof the concave portion region 48 is a shape in which convex portions arepresent with respect to the reference surface C. That is, in a casewhere the reference surface C is used as the reference, the uppersurface 48-1 is located at a position projecting upward with respect tothe reference surface C (=the lower surface 48-2), such that the concaveportion region 48 becomes a region in which fine convex portions areformed. Moreover, in other words, when the reference surface C is usedas the reference, the concave portion region 48 can be said to be aregion in which the convex portion is formed between the lower surface48-2 and the lower surface 48-2, such that fine convex portions areformed.

In a case where the reference surface B is used as a reference, a shapeof the concave portion region 48 is a shape in which concave portionsand convex portions are present with respect to the reference surface B.That is, in a case where the reference surface B is used as thereference, the lower surface 48-2 is located at a position depresseddownward with respect to the reference surface B (=the surface that isat the position between the upper surface 48-1 and the lower surface48-2), such that the concave portion region 48 can be said to be aregion in which fine concave portions are formed.

Furthermore, in a case where the reference surface B is used as thereference, the upper surface 48-1 is located at a position projectingupward with respect to the reference surface B, such that the concaveportion region 48 can be said to be a region in which fine convexportions are formed.

As described above, the concave portion region 48 is a region that canbe expressed as a region formed by the fine concave portions, a regionformed by the fine convex portions, or a region formed by the fineconcave portions and convex portions, depending on where the referencesurface is set, in cross-sectional view of the pixel 1.

In the following description, the concave portion region 48 will bedescribed by taking a case where the reference surface A, that is, theupper surface 48-1 is used as the reference surface as an example, and adescription will be continued on the assumption that the concave portionregion 48 is a region in which the fine concave portions are formed.

In the concave portion region 48, a pitch between the concave portionscorresponding to a period of the concave portions is set to, forexample, 250 nm or more.

In an example illustrated in FIG. 3 , a case where the concave portionregion 48 has a shape in which planes of the upper surface 48-1 and thelower surface 48-2 are combined with each other has been illustrated asan example, but a concave portion region 48 having a shape asillustrated in FIG. 4 is also included in the concave portion region 48to which the present technology is applied.

The concave portion region 48 illustrated in FIG. 4 is formed in atriangular shape in cross-sectional view. Even though a shape of theconcave portion region 48 is such a shape, a reference surface can beset, and concave portions or convex portions can be defined on the basisof the reference surface.

Since the concave portion region 48 illustrated in FIG. 4 is formed inthe triangular shape in cross-sectional view, as an example of thereference surface, a surface connecting vertices to each other is set tobe the reference surface.

In cross-sectional view, a surface including a line connecting verticesclose to the transparent insulating film 46 among the vertices of thetriangular shape of the concave portion region 48 to each other isdefined as a reference surface A. A surface including a line connectingvertices close to a bottom side, in other words, vertices close to thesemiconductor region 42, among the vertices of the triangular shape ofthe concave portion region 48 to each other is defined as a referencesurface C. A surface between the reference surface A and the referencesurface C is defined as a reference surface B.

Even in a case where the reference surface is set at a position of thevertex of the triangular shape of the concave portion region 48 asdescribed above, a shape of the concave portion region 48 can beexpressed differently depending on where the reference surface islocated, similar to a case described with reference to FIG. 3 .

That is, in a case where the reference surface A is used as a reference,a shape of the concave portion region 48 is a shape in which downwardtriangular (valley-shaped) concave portions are present with respect tothe reference surface A. That is, in a case where the reference surfaceA is used as the reference, a valley region is located below thereference surface A and corresponds to the concave portion. Therefore,the concave portion region 48 becomes a region in which fine concaveportions are formed. Moreover, in other words, when the referencesurface A is used as the reference, the concave portion region 48 can besaid to be a region in which the concave portion is formed between avertex of a triangle and a vertex of an adjacent triangle, such thatfine concave portions are formed.

In a case where the reference surface C is used as a reference, a shapeof the concave portion region 48 is a shape in which upward triangular(peak-shaped) convex portions are present with respect to the referencesurface C. That is, in a case where the reference surface C is used asthe reference, a peak region is located above the reference surface Cand corresponds to the convex portion. Therefore, the concave portionregion 48 becomes a region in which fine convex portions are formed.Moreover, in other words, when the reference surface C is used as thereference, the concave portion region 48 can be said to be a region inwhich the convex portion is formed between vertices of a bottom side ofthe triangular shape, such that fine head portions are formed.

In a case where the reference surface B is used as a reference, a shapeof the concave portion region 48 is a shape in which concave portionsand convex portions (valleys and peaks) are present with respect to thereference surface B. That is, in a case where the reference surface B isused as the reference, the concave portions that become the valleys arepresent below the reference surface B and the convex portions thatbecome the peaks are present above the reference surface B. Therefore,the concave portion region 48 can be said to be a region including fineconcave portions and convex portions.

As described above, even though a shape of the concave portion region 48is a zigzag shape in which the peaks and the valleys are present asillustrated in FIG. 4 , the concave portion region 48 can be defined tobe a region that can be expressed as a region formed by the fine concaveportions, a region formed by the fine convex portions, or a regionformed by the fine concave portions and convex portions, depending onwhere the reference surface is set, in cross-sectional view of the pixel1.

Furthermore, in the concave portion region 48 illustrated in FIG. 3 orFIG. 4 , for example, in a case where the reference surface is aninterface between the flattening film 50 and the transparent insulatingfilm 46, the concave portion region 48 has a shape in which regions(valleys) having a depression are present, and can thus be said to be aregion formed by the fine concave portions.

Furthermore, in a case where the reference surface is an interfacebetween the P-type semiconductor region 41 and the N-type semiconductorregion 42, the concave portion region 48 has a shape in which projectingregions (peaks) are present, and can thus be said to be a region formedby the fine convex portions.

As described above, in cross-sectional view of the pixel 2, apredetermined flat surface is used as the reference surface, and a shapeof the concave portion region 48 can also be expressed depending onwhether portions having a valley shape with respect to the referencesurface are formed or portions having a peak shape with respect to thereference surface are formed.

Moreover, as will be described later with reference to FIG. 11 , aconfiguration in which a flat portion 53 is formed between the pixels 2can also be adopted. The flat portion 53 is a region provided byproviding a region of a predetermined width in which the concave portionregion 48 is not formed between the pixels 2 e at an interface on thelight receiving surface side of the semiconductor substrate 12. Asurface including the flat portion 53 may be used as the referencesurface.

Referring to FIG. 11 , in case where the surface including the flatportion 53 is used as the reference surface, the concave portion region48 can be said to have a shape having portions depressed downward withrespect to the reference surface, in other words, valley-shapedportions, and can thus be said to be a region in which fine concaveportions are formed.

As described above, the concave portion region 48 is a region that canbe expressed as a region formed by the fine concave portions, a regionformed by the fine convex portions, or a region formed by the fineconcave portions and convex portions, depending on where the referencesurface is set, in cross-sectional view of the pixel 1.

Moreover, the concave portion region 48 can be expressed as forming theregion formed by the fine concave portions, forming the region formed bythe fine convex portions, or forming the region formed by the fineconcave portions, depending on a method of forming the concave portionregion 48.

For example, in a case where the concave portion region 48 illustratedin FIG. 3 is formed, that is, in a case where the concave portion region48 having a shape in which the upper surface 48-1 is formed to be largerthan the lower surface 48-2 is formed, it can be said that a portionthat becomes the concave portion is formed and it can be said that aportion that becomes the convex portion is left, by shaving thesubstrate (semiconductor substrate 12).

In a case where a shaving amount of the substrate exceeds 50%, an areaof the concave portion is formed to be larger than that of the convexportion, such that an amount of the shaved substrate (silicon) becomes astate where it is larger than that of the remaining substrate. In otherwords, a case of such a method of forming the concave portion region isformation in a situation where the concave portion is dominant, and itcan be expressed that the concave portion region 48 is formed byproviding a plurality of convex portions.

Furthermore, in a case where a shaving amount of the substrate is 50% orless, an area of the concave portion is formed to be smaller than thatof the convex portion, such that an amount of the shaved substrate(silicon) becomes a state where it is smaller than that of the remainingsubstrate. In other words, a case of such a method of forming theconcave portion region is formation in a situation where the convexportion is dominant, and it can be expressed that the concave portionregion 48 is formed by providing a plurality of concave portions.

Consequently, according to the method of forming the concave portionregion 48, in a case where the concave portion becomes dominant, it canbe expressed that the plurality of convex portions is provided and in acase where the substrate becomes dominant, it can be expressed that theplurality of concave portions is provided.

As described above, depending on the method of forming a concave portionregion 48, the concave portion region 48 is a region that can beexpressed as a region formed by the fine concave portions, a regionformed by the fine convex portions, or a region formed by the fineconcave portions and convex portions, in cross-sectional view of thepixel 1.

In the following description, a description will be continued on theassumption that the concave portion region 48 is the region formed bythe fine concave portions, but the concave portion region 48 is anexpression including a region such as the region formed by the fineconvex portions or the region formed by the fine concave portions andconvex portions, as described above.

Pixel Structure According to Second Embodiment

FIG. 5 is a diagram illustrating a cross-sectional configuration exampleof a pixel 2 b according to a second embodiment.

The cross-sectional configuration example of the pixel 2 b illustratedin FIG. 5 has a configuration in which the color filter layer 51 isremoved from the configuration of the pixel 2 a according to the firstembodiment illustrated in FIG. 2 . The present technology can also beapplied to the pixel 2 b having a structure in which the color filterlayer 51 is not present.

The pixel 2 b according to the second embodiment can be applied to, forexample, a pixel receiving infrared light (IR). As described later,according to the pixel 2 b to which the present technology is applied,an optical path length can be increased, and it becomes thus possible toimprove sensitivity without increasing a thickness of the pixel 2 b, inother words, a thickness of a semiconductor substrate 12, even in theinfrared light having a long wavelength.

<Effect of Pixel Structures According to First and Second Embodiments>

FIGS. 6A and 6B are diagrams for describing an effect of a pixelstructure of the pixel 2 a illustrated in FIG. 2 . Since a similareffect can also be obtained in the pixel 2 b illustrated in FIG. 5 ,here, a description will be continued by taking the pixel structure ofthe pixel 2 a illustrated in FIG. 2 as an example. Furthermore, aneffect described here is an effect similarly obtained in an embodimentas described later.

FIG. 6A is a diagram for describing an effect by the concave portionregion 48.

Reflection of incident light is prevented by the concave portion region48. Therefore, sensitivity of the solid-state imaging device 1 can beimproved.

FIG. 6B is a diagram for describing an effect by an inter-pixel lightshielding portion 47 having a trench structure.

Conventionally, in a case where the inter-pixel light shielding portion47 is not provided, incident light scattered by the concave portionregion 48 might pass through a photoelectric conversion region(semiconductor regions 41 and 42). The inter-pixel light shieldingportion 47 has an effect of reflecting the incident light scattered bythe concave portion region 48 to confine the incident light in thephotoelectric conversion region. Therefore, an optical distance forabsorbing silicon is extended, and sensitivity can thus be improved.

Furthermore, since the inter-pixel light shielding portion 47 is dug ina state where it penetrates through the semiconductor substrate 12, inother words, in a state where it reaches the multilayer wiring layer 21,the inter-pixel light shielding portion 47 has an effect of morecertainly confining the incident light in the photoelectric conversionregion. Moreover, although there is also incident light reflected by themultilayer wiring layer 21, the incident light reflected by themultilayer wiring layer 21 can also be confined in the photoelectricconversion region, such that the sensitivity can be further improved.

Assuming that a refractive index (n1) of the inter-pixel light shieldingportion 47 is 1.5 (corresponding to SiO₂) and a refractive index (n2) ofthe semiconductor region 41 in which the photoelectric conversion regionis formed is 4.0, a waveguide effect (photoelectric conversion region:core, inter-pixel light shielding portion 47: clad) occurs due to the adifference (n1<n2) between the refractive indices, and the incidentlight is thus confined in the photoelectric conversion region. Theconcave portion region 48 has a disadvantage of deteriorating colormixing due to light scattering, but can counteract the deterioration ofthe color mixing by combining with the inter-pixel light shieldingportion 47, and further has an advantage of improving photoelectricconversion efficiency by increasing an incident angle of the incidentlight traveling in the photoelectric conversion region.

Furthermore, since it becomes possible to extend the optical distancefor absorbing silicon, a structure of increasing the optical path lengthcan be obtained as described above. Therefore, it becomes possible toefficiently condense even incident light having a long wavelength on thephotodiode PD, such that it becomes possible to improve sensitivity evenfor the incident light having the long wavelength.

<Optimal Condition Example of Pixel Structure>

Optimal conditions at various places of the pixel 2 a will be describedwith reference to FIG. 7 .

In the embodiment described above, the concave portion region 48 hasbeen formed in the entire region on the light receiving surface side ofthe semiconductor regions 41 and 42 in which the photodiode PD isformed.

However, a concave portion arrangement region L1 (concave portionarrangement width L1) of the concave portion region 48 can be formedonly at a pixel central portion in a region of a predetermined ratio toa pixel region L4 (pixel width L4), as illustrated in FIG. 7 . Then, itis desirable that the concave portion arrangement region L1 of theconcave portion region 48 is a region of approximately 80% of the pixelregion L4.

The light condensed by the on-chip lens 52 is focused on the center of aregion of a sensor (photodiode PD), which is the photoelectricconversion region. Therefore, the closer to the center of the sensor,the stronger the light intensity, and the more distant from the centerof the sensor, the weaker the light intensity In a region distant fromthe center of the sensor, there are many diffracted light noisecomponents, that is, color mixture noise components to adjacent pixels.

Therefore, a concave portion structure is not formed in the vicinity ofthe inter-pixel light shielding portion 47, such that light scatteringcan be suppressed and noise can be suppressed. The concave portionarrangement region L1 of the concave portion region 48 is changeddepending on a difference in an upper layer structure such as a pixelsize, a curvature of the on-chip lens, and a total thickness of thepixel 2 a, but it is desirable that the on-chip lens 52 is generally aregion of approximately 80% of the pixel region L4 in order to condensespot light on a region of 80% of the center of the region of the sensor.

Furthermore, a size (convex portion formed between the concave portions)of the concave portion of the concave portion region 48 can be formed tobe different for every color. As a size of the convex portion (a sizefrom the bottom side to the vertex of the concave portion), a height, anarrangement area (an area in which the convex portion is formed in planview), and a pitch can be defined.

Here, a description will be provided using the convex portion on theassumption that a depth of the concave portion is equal to the height ofthe convex portion and the convex portion is a portion of the uppersurface 48-1 based on the reference surface C as described withreference to FIG. 3 .

The height of the convex portion becomes lower as a wavelength of theincident light becomes shorter. That is, assuming that a height of aconvex portion of a red pixel 2 a is hR, a height of a convex portion ofa green pixel 2 a is hG, and a height of a convex portion of a bluepixel 2 a is hB, the concave portion regions 48 can be formed so that amagnitude relation of

hR>hG>hB

is established.

Furthermore, the arrangement area of the convex portion becomes smalleras the wavelength of the incident light becomes shorter. That is,assuming that an arrangement area of the convex portion of the red pixel2 a is xR, an arrangement area of the convex portion of the green pixel2 a is xG, and an arrangement area of the convex portion of the bluepixel 2 a is xB, the concave portion regions 48 can be formed so that amagnitude relation of xR>xG>xB is established. A width of thearrangement area in one direction corresponds to the concave portionarrangement width L1 in FIG. 7 .

The pitch between the convex portions becomes lower as the wavelength ofthe incident light becomes shorter. That is, assuming that a pitchbetween the convex portions of the red pixel 2 a is pR, a pitch betweenthe convex portions of the green pixel 2 a is pG, and a pitch betweenthe convex portion of the blue pixel 2 a is pB, the concave portionregions 48 can be formed so that a magnitude relation of

pR>pG>pB

is established.

Furthermore, the pitch between the convex portions can be set to be adivisor of a pixel pitch between two-dimensionally arranged pixels, inother words, a pitch between the pixels 2 of the pixel array unit 3 (seeFIG. 1 ).

The concave portion region 48 satisfying such conditions can be formedby, for example, wet etching using a resist pattern as a mask.

Next, a groove width L2 of the inter-pixel light shielding portion 47necessary for preventing leakage of the incident light into the adjacentpixels and totally reflecting the incident light will be described.

It is sufficient if the groove width L2 of the inter-pixel lightshielding portion 47 may be 40 nm or more, assuming that a wavelength(λ) of the incident light is 600 nm, the refractive index (n2) of thesemiconductor region 41 is 4.0, the refractive index (n1) of theinter-pixel light shielding portion 47 is 1.5 (corresponding to SiO₂),and an incident angle (θ) from the semiconductor region 41 to theinter-pixel light shielding portion 47 is 60°. However, it is desirablethat the groove width L2 of the inter-pixel light shielding portion 47is 200 nm or more from the viewpoint of a margin satisfying opticalcharacteristics and a process embedding property.

A digging amount L3 of the inter-pixel light shielding portion 47 willbe described.

The larger the digging amount L3 of the inter-pixel light shieldingportion 47, the larger the effect of suppressing color mixing.Therefore, the digging amount L3 can be set to a size equal to thethickness of the semiconductor substrate 12. That is, the inter-pixellight shielding portion 47 is formed in a state where it penetratesthrough the semiconductor substrate 12. In this case, the digging amountL3 is the same as the thickness of the semiconductor substrate 12.

As illustrated in FIG. 7 , a case where the inter-pixel light shieldingportion 47 has a dug shape without a taper is exemplified, but theinter-pixel light shielding portion 47 may have a tapered shape.

The inter-pixel light shielding portion 47 has a tapered shape differingdepending on whether or not the inter-pixel light shielding portion 47is dug from the front surface side of the semiconductor substrate 12configuring the pixel 2 a, that is, a side close to the multilayerwiring layer 21, which is a lower side in FIG. 7 , or is dug from theback surface side of the semiconductor substrate 12, that is, anincident surface side, which is an upper side in FIG. 7 , at the time ofmanufacturing the inter-pixel light shielding portion 47.

The inter-pixel light shielding portion 47 has a tapered shape in whicha side where the digging is started is wide and a side where the diggingis ended is narrow. Therefore, in a case where the semiconductorsubstrate 12 is dug from a front surface side of the pixel 2 a, theinter-pixel light shielding portion 47 has a tapered shape in which aside of the semiconductor substrate 12 close to the multilayer wiringlayer 21 is wide and a side of the semiconductor substrate 12 close tothe transparent insulating film 46 is narrow. Furthermore, in a casewhere the semiconductor substrate 12 is dug from a back surface side ofthe pixel 2 a, the inter-pixel light shielding portion 47 has a taperedshape in which a side of the semiconductor substrate 12 close to thetransparent insulating film 46 is wide and a side of the semiconductorsubstrate 12 close to the multilayer wiring layer 21 is narrow.

In a case where the inter-pixel light shielding portion 47 has thetapered shape, for example, assuming that the refractive index (n1) ofthe inter-pixel light shielding portion 47 is 1.5 (corresponding toSiO₂) and the refractive index (n2) of the P-type semiconductor region41 is 4.0, an interface reflectance is very high, and a shape of theinter-pixel light shielding portion 47 can thus be a forward tapered orreverse tapered shape within a range of 0° to 30°.

Pixel Structure According to Third Embodiment

FIG. 8 is a diagram illustrating a cross-sectional configuration exampleof a pixel 2 c according to a third embodiment.

In FIG. 8 , portions corresponding to those of the first embodimentillustrated in FIG. 2 will be denoted by the same reference numerals,and a description thereof will be appropriately omitted.

The third embodiment illustrated in FIG. 8 is different from the firstembodiment described above in that a metal light shielding portion 101is newly provided with filling a central portion of an inter-pixel lightshielding portion 47 having a trench structure arranged between thepixels 2 c with, for example, a metal material such as tungsten (W) oraluminum (Al).

Furthermore, in the third embodiment, a transparent insulating film 46stacked on a front surface of a pinning layer 45 is formed conformallyusing, for example, a sputtering method and the like.

In a solid-state imaging device 1 according to the third embodiment,color mixing can be further suppressed by further providing the metallight shielding portion 101. Furthermore, by providing the metal lightshielding portion 101, it becomes possible to reflect incident light ina photoelectric conversion region and condense the incident light bysemiconductor regions 41 and 42 in which a photodiode PD is formed, andit is thus possible to improve sensitivity.

Pixel Structure According to Fourth Embodiment

FIG. 9 is a diagram illustrating a cross-sectional configuration exampleof a pixel 2 d according to a fourth embodiment.

The pixel 2 d according to the fourth embodiment has a configurationsimilar to that of the pixel 2 a according to the first embodimentexcept that a material filled in an inter-pixel light shielding portion47 is a polysilicon (Poly Si) layer 102. That is, the inter-pixel lightshielding portion 47 of the pixel 2 d includes a pinning layer 45 andthe polysilicon layer 102.

Furthermore, as illustrated in the pixel 2 d illustrated in FIG. 10 ,only the polysilicon layer 102 may be formed in the inter-pixel lightshielding portion 47 without forming the pinning layer 45 in theinter-pixel light shielding portion 47.

As described above, the inter-pixel light shielding portion 47 may beformed by filling polycrystalline silicon such as the polysilicon 102 inthe inter-pixel light shielding portion 47. Furthermore, a materialhaving a lower refractive index than that of silicon configuring asemiconductor substrate 12 may be further added as an insulating film inthe inter-pixel light shielding portion 47.

Pixel Structure According to Fifth Embodiment

Other embodiments of pixel structures will be described with referenceto FIGS. 11 to 19 . In FIGS. 11 to 19 , a description will be providedusing pixel structures illustrated in a simplified manner as comparedwith the cross-sectional configuration example as illustrated in FIG. 2, and the respective corresponding components may be denoted bydifferent reference numbers.

Furthermore, in other embodiments of pixel structures described below, adescription will be continued by taking a case where a pixel includes acolor filter layer 51 as in the pixel 2 a according to the firstembodiment as an example, but the present technology can also be appliedto a pixel that does not include the color filter layer 51 as in thepixel 2 b according to the second embodiment.

FIG. 11 is a diagram illustrating a cross-sectional configurationexample of a pixel 2 e according to a fifth embodiment.

Although there are portions that overlap the description describedabove, a configuration of a solid-state imaging device 1 will bedescribed again with reference to FIG. 11 As illustrated in FIG. 11 ,the solid-state imaging device 1 is configured by stacking anantireflection film 111, a transparent insulating film 46, a colorfilter layer 51, and an on-chip lens 52 on a semiconductor substrate 12in which an N-type semiconductor region 42 configuring a photodiode PDis formed for every pixel 2 a.

The antireflection film 111 has a stacked structure in which, forexample, a fixed charge film and an oxide film are stacked, and forexample, an insulating thin film having a high dielectric constant(high-k) by an atomic layer deposition (ALD) method can be used as theantireflection film 111. Specifically, hafnium oxide (HfO₂), aluminumoxide (Al₂O₃), titanium oxide (TiO₂), strontium titanium oxide (STO), orthe like, can be used. In the example of FIG. 11 , the antireflectionfilm 111 is configured by stacking a hafnium oxide film 112, an aluminumoxide film 113, and a silicon oxide film 114.

Moreover, a light shielding film 49 is formed between the pixels 2 e soas to be stacked on the antireflection film 111. A single-layer metalfilm such as titanium (Ti), titanium nitride (TiN), tungsten (W),aluminum (Al), or tungsten nitride (WN), is used as the light shieldingfilm 49. Alternatively, a stacked film of these metals (for example, astacked film of titanium and tungsten, a stacked film of titaniumnitride and tungsten, or the like) may be used as the light shieldingfilm 49.

In the solid-state imaging device 1 configured as described above, inthe pixel 2 e according to the fifth embodiment, a flat portion 53 isprovided by providing a region of a predetermined width in which aconcave portion region 48 is not formed between the pixels 2 e at alight receiving surface side interface of the semiconductor substrate12. As described above, the concave portion region 48 is provided byforming a fine concave structure, and the flat portion 53 is provided bymaking a flat surface remain without forming the fine concave structurein a region between the pixels 2 e. As described above, by adopting apixel structure in which the flat portion 53 is provided, it is possibleto suppress generation of diffracted light in a region (pixel separationregion) of a predetermined width, which is the vicinity of anotheradjacent pixel 2 e, to prevent generation of color mixing.

That is, it has been known that in a case where the concave portionregion 48 is formed in the semiconductor substrate 12, diffraction ofvertical incident light occurs, and for example, as an interval (pitch)between concave portions increases, a component of diffracted lightincreases, such that a ratio of light incident on another adjacent pixel2 increases.

On the other hand, in the solid-state imaging device 1, by providing theflat portion 53 in the region of the predetermined width between thepixels 2 e in which it is easy for the diffracted light to leak toanother adjacent pixel 2 e, the diffraction of the vertical incidentlight is not generated in the flat portion 53, such that it is possibleto prevent the generation of the color mixing.

In the pixel 2 e illustrated in FIG. 11 , a pixel separating portion 54separating the pixels 2 e from each other is formed in the semiconductorsubstrate 12. The pixel separating portion 54 is formed in a portioncorresponding to the inter-pixel light shielding portion 47 in the firstto fourth embodiments described above.

The pixel separating portion 54 is formed by forming a trenchpenetrating through the semiconductor substrate 12 between the N-typesemiconductor regions 42 configuring the photodiodes PD, forming analuminum oxide film 113 on an inner surface of the trench, and furtherembedding an insulator 55 into the trench at the time of forming thesilicon oxide film 114.

Note that as in the pixel d (see FIG. 9 or FIG. 10 ) according to thefourth embodiment, a configuration in which a portion of the siliconoxide film 114 that is filled in the pixel separating portion 54includes a polysilicon layer 102 can be applied.

By configuring such a pixel separating portion 54, adjacent pixels 2 eare electrically completely separated from each other by the insulator55 embedded in the trench. Therefore, it is possible to prevent chargesgenerated inside the semiconductor substrate 12 from leaking to theadjacent pixel 2 e.

Pixel Structure According to Sixth Embodiment

FIG. 12 is a diagram illustrating a cross-sectional configurationexample of a pixel 2 f according to a sixth embodiment.

In FIG. 12 , a basic configuration of a solid-state imaging device 1 iscommon to the configuration illustrated in FIG. 11 . In the pixel 2 faccording to the sixth embodiment, a pixel separating portion 54Acompletely separating the pixels 2 f from each other is formed in asemiconductor substrate 12.

The pixel separating portion 54A is formed by digging a trenchpenetrating through the semiconductor substrate 12 between N-typesemiconductor regions 42 configuring photodiodes PD, forming an aluminumoxide film 113 on an inner surface of the trench, embedding an insulator55 into the trench at the time of forming a silicon oxide film 114, andfurther embedding a light shielding object 56 at the time of forming alight shielding film 49 inside the insulator 55. The light shieldingobject 56 includes a metal having a light shielding property so as to beintegrated with the light shielding film 49.

By configuring such a pixel separating portion 54A, adjacent pixels 2 fare electrically separated from each other by the insulator 55 embeddedin the trench, and are optically separated from each other by the lightshielding object 56. Therefore, it is possible to prevent chargesgenerated inside the semiconductor substrate 12 from leaking to theadjacent pixel 2 f, and it is possible to prevent light from an obliquedirection from leaking to the adjacent pixel 2 f.

Then, also in the pixel 2 f according to the sixth embodiment, byadopting a pixel structure in which a flat portion 53 is provided, it ispossible to suppress generation of diffracted light in a pixelseparation region to prevent generation of color mixing.

Pixel Structure According to Seventh Embodiment

FIG. 13 is a diagram illustrating a cross-sectional configurationexample of a pixel 2 g according to a seventh embodiment.

In FIG. 13 , a basic configuration of a solid-state imaging device 1 iscommon to the configuration illustrated in FIG. 11 . In the pixel 2 gaccording to the seventh embodiment, a pixel separating portion 54Bcompletely separating the pixels 2 g from each other is formed in asemiconductor substrate 12.

The pixel separating portion 54B is formed by digging a trenchpenetrating through the semiconductor substrate 12 between N-typesemiconductor regions 42 configuring photodiodes PD, forming an aluminumoxide film 113 on an inner surface of the trench, embedding an insulator55 into the trench at the time of forming a silicon oxide film 114, andfurther embedding a light shielding object 56 in the trench.

The pixel separating portion 54B of the pixel 2 g according to theseventh embodiment differs from the pixel 2 f according to the sixthembodiment in that the light shielding film 49 is not provided in theflat portion 53.

By configuring such a pixel separating portion 54B, adjacent pixels 2 gare electrically separated from each other by the insulator 55 embeddedin the trench, and are optically separated from each other by the lightshielding object 56. Therefore, it is possible to prevent chargesgenerated inside the semiconductor substrate 12 from leaking to theadjacent pixel 2 g, and it is possible to prevent light from an obliquedirection from leaking to the adjacent pixel 2 g.

Then, also in the pixel 2 g according to the seventh embodiment, byadopting a pixel structure in which the flat portion 53 is provided, itis possible to suppress generation of diffracted light in a pixelseparation region to prevent generation of color mixing.

Pixel Structure According to Eighth Embodiment

FIG. 14 is a diagram illustrating a cross-sectional configurationexample of a pixel 2 h according to an eighth embodiment.

In FIG. 14 , a basic configuration of a solid-state imaging device 1 iscommon to the configuration illustrated in FIG. 11 . In the pixel 2 haccording to the eighth embodiment, a concave portion region 48A has ashape in which a depth of a concave portion of the concave portionregion 48 becomes shallow in the vicinity of the periphery of the pixel2 h, and a pixel separating portion 54 is also formed.

That is, as illustrated in FIG. 14 , in the concave portion region 48A,the concave portion configuring the concave portion region 48A is formedto have a shallow depth in a peripheral portion of the pixel 2 h, thatis, in a portion which is the vicinity of another adjacent pixel 2 h,for example, as compared with the concave portion region 48 illustratedin FIG. 11 .

As described above, by forming a concave-convex structure at a shallowdepth in the peripheral portion of the pixel 2 h, it is possible tosuppress generation of diffracted light in the peripheral portion of thepixel 2 h. Also in the pixel 2 h according to the eighth embodiment, byadopting a pixel structure in which a flat portion 53 is provided, it ispossible to suppress generation of diffracted light in a pixelseparation region to further prevent generation of color mixing.

By forming such a concave portion region 48A, it is possible to suppressthe generation of the diffracted light in the peripheral portion of thepixel 2 h, and it is possible to electrically separate adjacent pixels 2h from each other by the pixel separating portion 54. Then, also in asixth variation of a pixel structure, by adopting a pixel structure inwhich a flat portion 53 is provided, it is possible to suppressgeneration of diffracted light in a pixel separation region to furtherprevent generation of color mixing.

Pixel Structure According to Ninth Embodiment

FIG. 15 is a diagram illustrating a cross-sectional configurationexample of a pixel 2 i according to a ninth embodiment.

In FIG. 15 , a basic configuration of a solid-state imaging device 1 iscommon to the configuration illustrated in FIG. 11 . In the pixel 2 iaccording to the ninth embodiment, a concave portion region 48A has ashape in which a depth of a concave portion configuring the concaveportion region 48A becomes shallow in the vicinity of the periphery ofthe pixel 2 i, and a pixel separating portion 54A is formed.

By forming such a concave portion region 48A, it is possible to suppressgeneration of diffracted light in a peripheral portion of the pixel 2 i,and it is possible to electrically and optically separate adjacentpixels 2 i from each other by the pixel separating portion 54A. Then,also in the ninth embodiment of the pixel structure, by adopting a pixelstructure in which a flat portion 53 is provided, it is possible tosuppress generation of diffracted light in a pixel separation region tofurther prevent generation of color mixing.

Pixel Structure According to Tenth Embodiment

FIG. 16 is a diagram illustrating a cross-sectional configurationexample of a pixel 2 j according to a tenth embodiment.

In FIG. 16 , a basic configuration of a solid-state imaging device 1 iscommon to the configuration illustrated in FIG. 11 . In the pixel 2 jaccording to the tenth embodiment, a concave portion region 48A has ashape in which a depth of a concave portion configuring the concaveportion region 48A becomes shallow in the vicinity of the periphery ofthe pixel 2 j, and a pixel separating portion 54B is formed.

By forming such a concave portion region 48A, it is possible to suppressgeneration of diffracted light in a peripheral portion of the pixel 2 j,and it is possible to electrically and optically separate adjacentpixels 2 j from each other by the pixel separating portion 54B. Then,also in the pixel 2 j according to the tenth embodiment, by adopting apixel structure in which a flat portion 53 is provided, it is possibleto suppress generation of diffracted light in a pixel separation regionto further prevent generation of color mixing.

Pixel Structure According to Eleventh Embodiment

FIG. 17 is a diagram illustrating a cross-sectional configurationexample of a pixel 2 k according to an eleventh embodiment.

In FIG. 17 , a basic configuration of a solid-state imaging device 1 iscommon to the configuration illustrated in FIG. 11 . In the pixel 2 kaccording to the eleventh embodiment, a region in which a concaveportion region 48B is formed is narrowed, and a pixel separating portion54 is formed.

That is, as illustrated in FIG. 17 , in the concave portion region 48B,a region forming the concave portion region 48B is reduced in aperipheral portion of the pixel 2 k, that is, in a portion which is thevicinity of another adjacent pixel 2 k, for example, as compared withthe concave portion region 48 illustrated in FIG. 11 . Therefore, a flatportion 53A is formed to be wider than the flat portion 53 of FIG. 11 .

As described above, by providing the flat portion 53A widely withoutforming the concave portion region 48B in the peripheral portion of thepixel 2 k, it is possible to suppress generation of diffracted light inthe peripheral portion of the pixel 2 k. Therefore, also in the pixel 2k according to the eleventh embodiment, it is possible to suppressgeneration of diffracted light in a pixel separation region to furtherprevent generation of color mixing.

Pixel Structure According to Twelfth Embodiment

FIG. 18 is a diagram illustrating a cross-sectional configurationexample of a pixel 2 m according to a twelfth embodiment.

In FIG. 18 , a basic configuration of a solid-state imaging device 1 iscommon to the configuration illustrated in FIG. 11 . In the pixel 2 maccording to the twelfth embodiment, a region in which a concave portionregion 48B is formed is narrowed, and a pixel separating portion 54A isformed.

By forming such a concave portion region 48B, it is possible to suppressgeneration of diffracted light in a peripheral portion of the pixel 2 m,and it is possible to electrically and optically separate adjacentpixels 2 m from each other by the pixel separating portion 54A. Then,also in the pixel 2 m according to the twelfth embodiment, by adopting apixel structure in which a flat portion 53A is widely provided, it ispossible to suppress generation of diffracted light in a pixelseparation region to further prevent generation of color mixing.

Pixel Structure According to Thirteenth Embodiment

FIG. 19 is a diagram illustrating a cross-sectional configurationexample of a pixel 2 n according to a thirteenth embodiment.

In FIG. 19 , a basic configuration of a solid-state imaging device 1 iscommon to the configuration illustrated in FIG. 11 . In the pixel 2 naccording to the thirteenth embodiment, a region in which a concaveportion region 48B is formed is narrowed, and a pixel separating portion54B is formed.

By forming such a concave portion region 48B, it is possible to suppressgeneration of diffracted light in a peripheral portion of the pixel 2 n,and it is possible to electrically and optically separate adjacentpixels 2 n from each other by the pixel separating portion 54B. Then,also in a twenty first variation of a pixel structure, by adopting apixel structure in which a flat portion 53A is widely provided, it ispossible to suppress generation of diffracted light in a pixelseparation region to further prevent generation of color mixing.

Application Example To Electronic Apparatus

The technology of the present disclosure is not limited to being appliedto a solid-state imaging device. That is, the technology of the presentdisclosure can be applied to all electronic apparatus using asolid-state imaging device in an image capturing unit (photoelectricconversion unit), such as an imaging device such as a digital stillcamera or a video camera, a portable terminal device having an imagingfunction, or a copy machine using a solid-state imaging device in animage reading unit. The solid-state imaging device may have a form inwhich it is formed as a single chip or may have a form of a module inwhich an imaging unit and a signal processing unit or an optical systemare packaged together and which has an imaging function.

FIG. 20 is a block diagram illustrating a configuration example of animaging device as an electronic apparatus according to the presentdisclosure.

The imaging device 200 of FIG. 20 includes an optical unit 201 includinga lens group and the like, a solid-state imaging device (imaging device)202 in which the configuration of the solid-state imaging device 1 ofFIG. 1 is adopted, and a digital signal processor (DSP) circuit 203which is a camera signal processing circuit. Furthermore, the imagingdevice 200 also includes a frame memory 204, a display unit 205, arecording unit 206, an operation unit 207, and a power supply unit 208.The DSP circuit 203, the frame memory 204, the display unit 205, therecording unit 206, the operation unit 207, and the power supply unit208 are connected to each other via a bus line 209.

The optical unit 201 takes in incident light (image light) from asubject and forms an image on an imaging surface of the solid-stateimaging device 202. The solid-state imaging device 202 converts anamount of incident light imaged on the imaging surface by the opticalunit 201 into an electric signal in pixel units and outputs the electricsignal as a pixel signal. As the solid-state imaging device 202, thesolid-state imaging device 1 of FIG. 1 , that is, the solid-stateimaging device having the improved sensitivity while suppressing thedeterioration of the color mixing can be used.

The display unit 205 includes, for example, a panel-type display devicesuch as a liquid crystal panel or an organic electroluminescence (EL)panel, and displays a moving image or a still image captured by thesolid-state imaging device 202. The recording unit 206 records themoving image or the still image captured by the solid-state imagingdevice 202 on a recording medium such as a hard disk or a semiconductormemory.

The operation unit 207 issues operation commands for various functionsof the imaging device 200 under an operation of a user. The power supplyunit 208 appropriately supplies various types of power that becomesoperation power of the DSP circuit 203, the frame memory 204, thedisplay unit 205, the recording unit 206, and the operation unit 207 tothese supply targets.

As described above, by using the solid-state imaging device 1 describedabove as the solid-state imaging device 202, it is possible to improvesensitivity while suppressing deterioration of color mixing. Therefore,also in the imaging device 200 such as a video camera, a digital stillcamera, and a camera module for a mobile apparatus such as a mobilephone, it is possible to improve image quality of a captured image.

The embodiments of the present disclosure are not limited to theembodiments described above, and various modifications can be madewithout departing from the scope of the present disclosure.

In the example described above, the solid-state imaging device in whichthe first conductivity-type is the P-type, the second conductivity-typeis the N-type, and electrons are signal charges has been described, butthe present disclosure can also be applied to a solid-state imagingdevice in which holes are signal charges. That is, it is possible toconfigure each of the semiconductor regions described above by anopposite conductivity-type semiconductor region so that the firstconductivity-type is the N-type and the second conductivity-type is theP-type.

Furthermore, the technology of the present disclosure is not limited tobeing applied to a solid-state imaging device that detects adistribution of an incident light amount of visible light to image thedistribution of the incident light amount as an image, and can beapplied to all solid-state imaging devices (physical quantitydistribution detecting devices) such as a solid-state imaging devicethat images a distribution of an incident amount of infrared rays,X-rays, particles, or the like, as an image, or a fingerprint detectionsensor that detects a distribution of another physical quantity such aspressure or capacitance to image the distribution of another physicalquantity as an image in a broad sense.

Application Example To Endoscopic Surgery System

The technology according to the present disclosure (the presenttechnology) can be applied to various products. For example, thetechnology according to the present disclosure may be applied to anendoscopic surgery system.

FIG. 21 is a view illustrating an example of a schematic configurationof an endoscopic surgery system to which the technology according to thepresent disclosure (the present technology) can be applied.

In FIG. 21 , an aspect in which an operator (surgeon) 11131 performssurgery on a patient 11132 on a patient bed 11133 using an endoscopicsurgery system 11000 is illustrated. As illustrated in FIG. 21 , theendoscopic surgery system 11000 includes an endoscope 11100, othersurgical tools 11110 such as a pneumoperitoneum tube 11111 or an energytreatment tool 11112, a support arm device 11120 supporting theendoscope 11100, and a cart 11200 on which various devices forendoscopic surgery are mounted.

The endoscope 11100 includes a lens barrel 11101 whose region of apredetermined length from a tip is inserted into the body cavity of thepatient 11132, and a camera head 11102 connected to a base end of thelens barrel 11101. The endoscope 11100 configured as a so-called rigidscope having a rigid lens barrel 11101 is illustrated in the illustratedexample, but the endoscope 11100 may be configured as a so-calledflexible scope having a flexible lens barrel.

An opening into which an objective lens is fitted is provided at the tipof the lens barrel 11101. A light source device 11203 is connected tothe endoscope 11100, such that light generated by the light sourcedevice 11203 is guided up to the tip of the lens barrel by a light guideextended inside the lens barrel 11101 and is irradiated toward anobservation target in the body cavity of the patient 11132 via theobjective lens. Note that the endoscope 11100 may be a forward-viewingendoscope or may be an oblique-viewing endoscope or a side-viewingendoscope.

An optical system and an imaging element are provided inside the camerahead 11102, and reflected light (observation light) from the observationtarget is condensed on the imaging element by the optical system. Theobservation light is photoelectrically converted by the imaging element,such that an electric signal corresponding to the observation light,that is, an image signal corresponding to an observation image isgenerated. The image signal is transmitted as RAW data to a cameracontrol unit (CCU) 11201.

The CCU 11201 includes a central processing unit (CPU), a graphicsprocessing unit (GPU), or the like, and comprehensively controlsoperations of the endoscope 11100 and a display device 11202. Moreover,the CCU 11201 receives the image signal from the camera head 11102 andperforms various image processing for displaying an image based on theimage signal, such as development processing (demosaic processing) andthe like, on the image signal.

The display device 11202 displays the image based on the image signal onwhich the image processing is performed by the CCU 11201, under controlof the CCU 11201.

The light source device 11203 includes a light source such as, forexample, a light emitting diode (LED), and supplies irradiated light tothe endoscope 11100 at the time of imaging a surgical site or the like.

The input device 11204 is an input interface for the endoscopic surgerysystem 11000. A user can input various information or variousinstructions to the endoscopic surgery system 11000 via the input device11204. For example, the user inputs an instruction to change imagingconditions (a type of irradiated light, a magnification, a focal length,and the like) by the endoscope 11100, and the like.

A treatment tool control device 11205 controls the drive of the energytreatment tool 11112 for cautery and incision of tissue, sealing of ablood vessel, or the like. A pneumoperitoneum device 11206 sends a gasinto the body cavity via the pneumoperitoneum tube 11111 in order toinflate the body cavity of the patient 11132 for the purpose of securinga visual field by the endoscope 11100 and securing a working space ofthe operator. A recorder 11207 is a device capable of recording variousinformation regarding the surgery. A printer 11208 is a device capableof printing the various information regarding the surgery in variousformats such as a text, an image, or a graph.

Note that the light source device 11203 that supplies the irradiatedlight at the time of imaging the surgical site to the endoscope 11100can include, for example, a white light source including an LED, a laserlight source, or a combination thereof. In a case where the white lightsource includes a combination of RGB laser light sources, it is possibleto control an output intensity and an output timing of each color (eachwavelength) with a high accuracy, and it is thus possible to adjust awhite balance of a captured image in the light source device 11203.Furthermore, in this case, by irradiating laser light from each of theRGB laser light sources to the observation target in a time divisionmanner and controlling the drive of the imaging element of the camerahead 11102 in synchronization with an irradiation timing of the laserlight, it is also possible to capture images corresponding to each ofRGB in a time division manner. According to such a method, it ispossible to obtain a color image without providing a color filter to theimaging element.

Furthermore, the drive of the light source device 11203 may becontrolled so as to change an intensity of light output by the lightsource device 11203 every predetermined time. By controlling the driveof the imaging element of the camera head 11102 in synchronization witha timing of the change in the intensity of the light to acquire imagesin a time division manner and synthesizing the images with each other,it is possible to generate a high dynamic range image without aso-called black spot and white spot.

Furthermore, the light source device 11203 may be configured to be ableto supply light of a predetermined wavelength band corresponding tospecial light observation. In the special light observation, forexample, so-called narrow band imaging in which a predetermined tissuesuch as a blood vessel in a mucous membrane surface layer is imaged withhigh contrast by irradiating light of a narrow band as compared withirradiated light (that is, white light) at the time of normalobservation using wavelength dependency of absorption of light in a bodytissue is performed. Alternatively, in the special light observation,fluorescence observation in which an image is obtained by fluorescencegenerated by irradiating excitation light may be performed. In thefluorescence observation, it can be performed to irradiate excitationlight to a body tissue and observe fluorescence from the body tissue(self-fluorescence observation) or locally inject a reagent such asindocyanine green (ICG) or the like to the body tissue and irradiateexcitation light corresponding to a fluorescence wavelength of thereagent to the body tissue to obtain a fluorescence image. The lightsource device 11203 can be configured to be able to supply the light ofthe narrow band and/or the excitation light corresponding to suchspecial light observation.

FIG. 22 is a block diagram illustrating an example of functionalconfigurations of the camera head 11102 and the CCU 11201 illustrated inFIG. 21 .

The camera head 11102 includes a lens unit 11401, an imaging unit 11402,a drive unit 11403, a communication unit 11404, and a camera headcontrol unit 11405. The CCU 11201 includes a communication unit 11411,an image processing unit 11412, and a control unit 11413. The camerahead 11102 and the CCU 11201 are communicably connected to each other bya transmission cable 11400.

The lens unit 11401 is an optical system provided at a connected portionwith the lens barrel 11101. Observation light taken in from the tip ofthe lens barrel 11101 is guided to the camera head 11102 and is incidenton the lens unit 11401. The lens unit 11401 is configured by combining aplurality of lenses including a zoom lens and a focus lens with eachother.

The number of imaging elements configuring the imaging unit 11402 may beone (a so-called single-plate type) or may be plural (a so-calledmulti-plate type). In a case where the imaging unit 11402 is configuredin the multi-plate type, for example, image signals corresponding toeach of RGB may be generated by each imaging element, and may besynthesized with each other to obtain a color image. Alternatively, theimaging unit 11402 may include a pair of imaging elements for acquiringrespectively image signals for a right eye and a left eye correspondingto a three-dimensional (3D) display. By performing the 3D display, theoperator 11131 can more accurately grasp a depth of a biological tissuein the surgical site. Note that in a case where the imaging unit 11402is configured in the multi-plate type, a plurality of lens units 11401may be provided to correspond to the respective imaging elements.

Furthermore, the imaging unit 11402 does not need to be necessarilyprovided in the camera head 11102. For example, the imaging unit 11402may be provided immediately after the objective lens, inside the lensbarrel 11101.

The drive unit 11403 includes an actuator, and moves the zoom lens andthe focus lens of the lens unit 11401 by a predetermined distance alongan optical axis under control of the camera head control unit 11405.Therefore, a magnification and a focus of the captured image by theimaging unit 11402 can be appropriately adjusted.

The communication unit 11404 includes a communication device fortransmitting and receiving various information to and from the CCU11201. The communication unit 11404 transmits the image signal obtainedfrom the imaging unit 11402 as RAW data to the CCU 11201 via thetransmission cable 11400.

Furthermore, the communication unit 11404 also receives a control signalfor controlling the drive of the camera head 11102 from the CCU 11201and supplies the control signal to the camera head control unit 11405.The control signal includes, for example, information regarding imagingconditions such as information indicating that a frame rate of thecaptured image is designated, information indicating that an exposurevalue at the time of capturing the image is designated, and/orinformation indicating that a magnification and a focus of the capturedimage are designated.

Note that the imaging conditions such as the frame rate, the exposurevalue, the magnification, and the focus, described above may beappropriately designated by the user or may be automatically set by thecontrol unit 11413 of the CCU 11201 on the basis of the acquired imagesignal. In the latter case, a so-called auto exposure (AE) function, anauto focus (AF) function, and an auto white balance (AWB) function aremounted in the endoscope 11100.

The camera head control unit 11405 controls the drive of the camera head11102 on the basis of the control signal from the CCU 11201 received viathe communication unit 11404.

The communication unit 11411 includes a communication device fortransmitting and receiving various information to and from the camerahead 11102. The communication unit 11411 receives the image signaltransmitted from the camera head 11102 via the transmission cable 11400.

Furthermore, the communication unit 11411 transmits the control signalfor controlling the drive of the camera head 11102 to the camera head11102. The image signal or the control signal can be transmitted bytelecommunication, optical communication or the like.

The image processing unit 11412 performs various image processing on theimage signal, which is the RAW data transmitted from the camera head11102.

The control unit 11413 performs various controls related to imaging ofthe surgical site or the like by the endoscope 11100 and display of thecaptured image obtained by the imaging of the surgical site or the like.For example, the control unit 11413 generates the control signal forcontrolling the drive of the camera head 11102.

Furthermore, the control unit 11413 causes the display device 11202 todisplay the captured image in which the surgical site or the like isimaged, on the basis of the image signal on which the image processingis performed by the image processing unit 11412. At this time, thecontrol unit 11413 may recognize various objects in the captured imageusing various image recognition technologies. For example, the controlunit 11413 can recognize a surgical tool such as forceps, a specificbiological site, bleeding, mist at the time of using the energytreatment tool 11112, and the like, by detecting a shape, a color, orthe like of an edge of an object included in the captured image. Thecontrol unit 11413 may cause various surgical support information to besuperimposed and displayed on an image of the surgical site using aresult of the recognition, when the control unit 11413 causes thedisplay device 11202 to display the captured image. The operationsupport information is superimposed and disposed and is presented to theoperator 11131, such that a burden on the operator 11131 can be reducedor the operator 11131 can certainly perform the surgery.

The transmission cable 11400 connecting the camera head 11102 and theCCU 11201 to each other is an electric signal cable corresponding tocommunication of an electric signal, an optical fiber corresponding tooptical communication, or a composite cable of the electric signal cableand the optical fiber.

Here, communication has been performed in a wired manner using thetransmission cable 11400 in the illustrated example, but communicationbetween the camera head 11102 and the CCU 11201 may be performed in awireless manner.

Application Example to Moving Body

The technology according to the present disclosure (the presenttechnology) can be applied to various products. For example, thetechnology according to the present disclosure may be realized as adevice mounted in any type of moving body such as a vehicle, an electricvehicle, a hybrid electric vehicle, a motorcycle, a bicycle, a personalmobility, an airplane, a drone, a ship, and a robot.

FIG. 23 is a block diagram illustrating a schematic configurationexample of a vehicle control system which is an example of a moving bodycontrol system to which the technology according to the presentdisclosure can be applied.

A vehicle control system 12000 includes a plurality of electroniccontrol units connected to each other via a communication network 12001.In the example illustrated in FIG. 23 , the vehicle control system 12000includes a drive system control unit 12010, a body system control unit12020, an outside-vehicle information detection unit 12030, aninside-vehicle information detection unit 12040, and an integratedcontrol unit 12050. Furthermore, as a functional configuration of theintegrated control unit 12050, a microcomputer 12051, an audio/imageoutput unit 12052, and an in-vehicle network interface (I/F) 12053 areillustrated.

The drive system control unit 12010 controls operations of devicesrelated to a drive system of the vehicle according to various programs.For example, the drive system control unit 12010 functions as a controldevice of a driving force generation device for generating a drivingforce of the vehicle, such as an internal combustion engine, a drivemotor, or the like, a driving force transfer mechanism for transferringthe driving force to wheels, a steering mechanism for adjusting asteering angle of the vehicle, and a braking device for generating abraking force of the vehicle.

The body system control unit 12020 controls operations of variousdevices mounted on a vehicle body according to various programs. Forexample, the body system control unit 12020 functions as a controldevice of a keyless entry system, a smart key system, a power windowdevice, or various lamps such as a headlamp, a back lamp, a brake lamp,a blinker, and a fog lamp. In this case, electric waves or signals ofvarious switches transmitted from a portable device substituting for akey can be input to the body system control unit 12020. The body systemcontrol unit 12020 receives inputs of these electric waves or signals,and controls a door lock device, a power window device, a lamp, and thelike of the vehicle.

The outside-vehicle information detection unit 12030 detects informationregarding the outside of the vehicle in which the vehicle control system12000 is mounted. For example, an imaging unit 12031 is connected to theoutside-vehicle information detection unit 12030. The outside-vehicleinformation detection unit 12030 causes the imaging unit 12031 tocapture a vehicle external image, and receives the captured image. Theoutside-vehicle information detection unit 12030 may perform objectdetection processing or distance detection processing of a person, avehicle, an obstacle, a sign, characters on a road surface, or the likeon the basis of the received image.

The imaging unit 12031 is an optical sensor receiving light andoutputting an electric signal depending on an amount of received light.The imaging unit 12031 can output the electric signal as an image or canoutput the electric signal as measured distance information.Furthermore, the light received by the imaging unit 12031 may be visiblelight or may be non-visible light such as infrared light.

The inside-vehicle information detection unit 12040 detects informationregarding the inside of the vehicle. For example, a driver statedetecting unit 12041 detecting a state of a driver is connected to theinside-vehicle information detection unit 12040. The driver statedetecting unit 12041 includes, for example, a camera imaging the driver,and the inside-vehicle information detection unit 12040 may calculate afatigue degree or a concentration degree of the driver or may determinewhether or not the driver is dozing, on the basis of detectedinformation input from the driver state detecting unit 12041.

The microcomputer 12051 can calculate a control target value of thedriving force generation device, the steering mechanism, or the brakingdevice on the basis of the information regarding the inside or theoutside of the vehicle acquired by the outside-vehicle informationdetection unit 12030 or the inside-vehicle information detection unit12040 and output a control command to the drive system control unit12010. For example, the microcomputer 12051 can perform cooperationcontrol for the purpose of realizing a function of an advanced driverassistance system (ADAS) including collision avoidance or shockmitigation of the vehicle, following traveling based on an inter-vehicledistance, vehicle speed maintenance traveling, collision warning of thevehicle, lane departure warning of the vehicle, and the like.

Furthermore, the microcomputer 12051 can perform cooperative control forthe purpose of automatic driving or the like in which the vehicleautonomously travels without depending on a driver's operation bycontrolling the driving force generating device, the steering mechanism,the braking device, or the like, on the basis of the surroundinginformation of the vehicle acquired by the outside-vehicle informationdetection unit 12030 or the inside-vehicle information detection unit12040.

Furthermore, the microcomputer 12051 can output a control command to thebody system control unit 12030 on the basis of the information regardingthe outside of the vehicle acquired by the outside-vehicle informationdetection unit 12030. For example, the microcomputer 12051 can performcooperative control for the purpose of achieving antiglare such asswitching a high beam into a low beam by controlling the headlampdepending on a position of the preceding vehicle or an oncoming vehicledetected by the outside-vehicle information detection unit 12030.

The audio/image output unit 12052 transmits at least one of an audiooutput signal or an image output signal to an output device capable ofvisually or auditorily notifying the passenger of the vehicle or theoutside of the vehicle of information. In the example of FIG. 23 , anaudio speaker 12061, a display unit 12062, and an instrument panel 12063are exemplified as the output device. The display unit 12062 mayinclude, for example, at least one of an on-board display or a head-updisplay.

FIG. 24 is a view illustrating an example of an installation position ofthe imaging unit 12031.

In FIG. 24 , a vehicle 12100 includes imaging units 12101, 12102, 12103,12104, and 12105 as the imaging unit 12031.

The imaging units 12101, 12102, 12103, 12104, and 12105 are provided,for example, at positions such as a front nose, side mirrors, a rearbumper, a back door, and an upper portion of a windshield of a vehicleinterior, of the vehicle 12100. The imaging unit 12101 provided on thefront nose and the imaging unit 12105 provided on the upper portion ofthe windshield of the vehicle interior mainly acquire images of a regionin front of the vehicle 12100. The imaging units 12102 and 12103provided on the side mirrors mainly acquire images of side regions ofthe vehicle 12100. The imaging units 12104 provided on the rear bumperor the back door mainly acquire an image of a region behind the vehicle12100. The imaging unit 12105 provided on the upper portion of thewindshield in the vehicle interior is mainly used to detect precedingvehicles, pedestrians, obstacles, traffic lights, traffic signs, lanes,or the like.

Note that FIG. 24 illustrates an example of imaging ranges of theimaging units 12101 to 12104. An imaging range 12111 indicates animaging range of the imaging unit 12101 provided on the front nose,imaging ranges 12112 and 12113 indicate imaging ranges of the imagingunits 12102 and 12103 provided on the side mirrors, respectively, and animaging range 12114 indicates an imaging range of the imaging unit 12104provided in the rear bumper or the back door. For example, by overlayingimage data captured by the imaging units 12101 to 12104 with each other,a bird's eye view image of the vehicle 12100 viewed from above can beobtained.

At least one of the imaging units 12101 to 12104 may have a function ofacquiring distance information. For example, at least one of the imagingunits 12101 to 12104 may be a stereo camera including a plurality ofimaging elements or may be an imaging element having pixels fordetecting a phase difference.

For example, the microcomputer 12051 can extract, in particular, athree-dimensional object that is the closest three-dimensional object ona traveling road of the vehicle 12100 and travels at a predeterminedspeed (for example, 0 km/h or more) in a direction that is substantiallythe same as that of the vehicle 12100 as the preceding vehicle bycalculating a distance to each three-dimensional object in the imagingranges 12111 to 12114 and a temporal change (relative speed to thevehicle 12100) in this distance on the basis of the distance informationacquired from the imaging units 12101 to 12104. Moreover, themicrocomputer 12051 can set an inter-vehicle distance to be secured inadvance in front of the preceding vehicle and perform automatic brakecontrol (including following stop control), automatic accelerationcontrol (including following start control), and the like. As describedabove, it is possible to perform the cooperative control for the purposeof the automatic driving or the like in which the vehicle autonomouslytravels without depending on the driver's operation.

For example, the microcomputer 12051 can classify and extractthree-dimensional object data regarding the three-dimensional objectsinto other three-dimensional objects such as a two-wheeled vehicle, anordinary vehicle, a large vehicle, a pedestrian, and a telephone pole,on the basis of the distance information acquired from the imaging units12101 to 12104, and use the three-dimensional object data for automaticavoidance of an obstacle. For example, the microcomputer 12051identifies obstacles around the vehicle 12100 as obstacles visible tothe driver of the vehicle 12100 and obstacles invisible to the driver ofthe vehicle 12100. Then, the microcomputer 12051 can perform drivingsupport for collision avoidance by determining a collision riskindicating a risk of collision with each obstacle and outputting awarning to the driver via the audio speaker 12061 or the display unit12062 or performing forced deceleration or avoidance steering via thedrive system control unit 12010 in a situation where the collision riskis a set value or more, such that there is a possibility of collision.

At least one of the imaging units 12101 to 12104 may be an infraredcamera detecting infrared light. For example, the microcomputer 12051can recognize a pedestrian by determining whether or not the pedestrianis present in the images captured by the imaging units 12101 to 12104.Such recognition of the pedestrian is performed by, for example, aprocedure for extracting feature points in images captured by theimaging units 12101 to 12104 as the infrared camera and a procedure ofperforming pattern matching processing on a series of feature pointsindicating an outline of an object to distinguish whether or not theobject is the pedestrian. When the microcomputer 12051 determines thatthe pedestrian is present in the images captured by the imaging units12101 to 12104 and recognizes the pedestrian, the audio/image outputunit 12052 controls the display unit 12062 to superimpose and display arectangular outline for emphasizing the recognized pedestrian.Furthermore, the audio/image output unit 12052 may control the displayunit 12062 to display an icon or the like indicating the pedestrian on adesired position.

In the present specification, a system refers to an entire deviceincluding a plurality of devices.

Note that effects described in the present specification are merelyexamples and are not limited, and other effects may be provided.

Note that the embodiments of the present technology are not limited tothe embodiments described above, and various modifications can be madewithout departing from the scope of the present technology.

Note that the present technology can also have the followingconfiguration.

(1)

-   A solid-state imaging device including:-   a substrate;-   a first photoelectric conversion region that is provided in the    substrate;-   a second photoelectric conversion region that is provided in the    substrate;-   a trench that is provided between the first photoelectric conversion    region and the second photoelectric conversion region and penetrates    through the substrate;-   a first concave portion region that has a plurality of concave    portions provided on a light receiving surface side of the    substrate, above the first photoelectric conversion region; and-   a second concave portion region that has a plurality of concave    portions provided on the light receiving surface side of the    substrate, above the second photoelectric conversion region.

(2)

-   The solid-state imaging device according to the above (1), in which    an insulating film is formed in the trench.

(3)

-   The solid-state imaging device according to the above (1) or (2), in    which the trench is filled with a metal material.

(4)

-   The solid-state imaging device according to the above (2), in which    a pinning layer is stacked between the substrate and the insulating    film.

(5)

-   The solid-state imaging device according to the above (2), in which    an antireflection film is stacked between the substrate and the    insulating film.

(6)

-   The solid-state imaging device according to any one of the above (1)    to (5), in which the concave portion region is formed at a central    portion of a pixel, the central portion of the pixel being a region    of a predetermined ratio to a pixel region.

(7)

-   The solid-state imaging device according to any one of the above (1)    to (5), in which the concave portion region is formed at a central    portion of a pixel, the central portion of the pixel being a region    of 80% of a pixel region.

(8)

-   The solid-state imaging device according to any one of the above (1)    to (7), in which a flat portion of a predetermined width in which    the concave portion region is not formed is provided between pixels    on the light receiving surface side.

(9)

-   An electronic apparatus including:-   a solid-state imaging device including:-   a substrate;-   a first photoelectric conversion region that is provided in the    substrate;-   a second photoelectric conversion region that is provided in the    substrate;-   a trench that is provided between the first photoelectric conversion    region and the second photoelectric conversion region and penetrates    through the substrate;-   a first concave portion region that has a plurality of concave    portions provided on a light receiving surface side of the    substrate, above the first photoelectric conversion region; and-   a second concave portion region that has a plurality of concave    portions provided on the light receiving surface side of the    substrate, above the second photoelectric conversion region.

REFERENCE SIGNS LIST

-   1 Solid-state imaging device-   2 Pixel-   3 Pixel array unit-   12 Semiconductor substrate-   41, 42 Semiconductor region-   45 Pinning layer-   46 Transparent insulating film-   47 Inter-pixel lighting shielding portion-   48 Antireflection portion-   49 Light shielding film-   50 Flattening film-   51 Color filter layer-   52 0n-chip lens-   101 Metal light shielding portion-   200 Imaging device-   202 Solid-state imaging device

1. A light detecting device, comprising: a substrate; a firstphotoelectric conversion region in the substrate; a second photoelectricconversion region adjacent to the first photoelectric conversion regionin a cross-sectional view; a trench between the first photoelectricconversion region and the second photoelectric conversion region,wherein the trench penetrates through the substrate; a first concaveportion region that has a plurality of concave portions on a lightreceiving surface side of the substrate, above the first photoelectricconversion region; a second concave portion region that has a pluralityof concave portions on the light receiving surface side of thesubstrate, above the second photoelectric conversion region; and a filmincluding hafnium on the first concave portion region and the secondconcave portion region, wherein the film is undisposed in the trench. 2.The light detecting device according to claim 1, wherein an insulatingfilm is in the trench.
 3. The light detecting device according to claim1, wherein the trench is filled with a metal material.
 4. The lightdetecting device according to claim 2, wherein a pinning layer isstacked between the substrate and the insulating film.
 5. The lightdetecting device according to claim 2, wherein an antireflection film isstacked between the substrate and the insulating film.
 6. The lightdetecting device according to claim 1, wherein the first concave portionregion is at a central portion of a first pixel, the central portion ofthe first pixel is a region of a specific ratio to a first pixel region.7. The light detecting device according to claim 1, wherein the firstconcave portion region is at a central portion of a first pixel, thecentral portion of the first pixel is a region of 80% of a first pixelregion.
 8. The light detecting device according to claim 1, wherein aflat portion of a specific width, in which each of the first concaveportion region and the second concave portion region is not formed, isbetween pixels on the light receiving surface side.
 9. An electronicapparatus, comprising: a light detecting device including: a substrate;a first photoelectric conversion region in the substrate; a secondphotoelectric conversion region adjacent to the first photoelectricconversion region in a cross-sectional view; a trench between the firstphotoelectric conversion region and the second photoelectric conversionregion, wherein the trench penetrates through the substrate; a firstconcave portion region that has a plurality of concave portions on alight receiving surface side of the substrate, above the firstphotoelectric conversion region; a second concave portion region thathas a plurality of concave portions on the light receiving surface sideof the substrate, above the second photoelectric conversion region; anda film including hafnium on the first concave portion region and thesecond concave portion region, wherein the film is undisposed in thetrench.